Over the past 10 years, medical therapy for men with symptomatic benign prostatic hyperplasia (BPH) has become first-line therapy. Well-designed clinical trials have defined the role of medical therapy for symptom reduction, improved quality of life and diminished the likelihood of disease progression. Phytotherapy for BPH has long been a popular therapeutic option in spite of the lack of compelling scientific information about the mechanism(s) of action, magnitude of symptom improvement, adverse effects or long-term preventative role of these extracts. The primary objective of this application is to determine whether the long-term use of saw palmetto or pygeum africanum delays or prevents the progression of clinical BPH as compared to placebo. Clinical progression will be specifically defined as symptom progression, acute urinary retention, recurrent infection or urosepsis, urinary incontinence or renal insufficiency. Patients will also be classified if they crossover to other BPH treatment options (watchful waiting, medical or invasive treatment). The secondary research questions include an assessment of the natural history of BPH in a well-defined population, differences over time between the 3 cohorts with respect to symptom score, quality of life, urinary flow rates, post void urinary residual, sexual function and prostate volume. The subgroup hypotheses will assess whether treatment response is related to symptom severity, urinary flow rate, residual urine, prostate size or prostate specific antigen hopefully providing some insight into the mechanism of action should these agents be proven effective. The study will enroll approximately 3000 men at 10 centers during the first 2 years. Patients will be followed at 3-month intervals for 4 to 6 years using standard outcome measures. This trial will determine whether saw palmetto or pygeum africanum are worthwhile alternative for the treatment of men with symptomatic BPH.